Operating method of microwave heating device and microwave annealing process using the same

ABSTRACT

An operating method of microwave heating device is provided, in which a holder is disposed in a heating chamber, and a plurality of microwave transmitters are arranged outside the heating chamber. A plurality of half-wave-rectified power supplies are provided to connect the microwave transmitters, and the half-wave-rectified power supplies have capacitances respectively. A plurality of longitudinal waveguides and a plurality of transverse waveguides are installed in between the heating chamber and the microwave transmitters. The capacitance of each of the capacitors of the half-wave-rectified power supplies is adjusted, such that the microwave power pulse bandwidth of the microwave transmitters are extended to produce a plurality of overlapped couplings, thereby multiplying microwave mode numbers. The half-wave-rectified power supplies supply power to the microwave transmitters, so that the microwaves are guided into the heating chamber by the longitudinal waveguides and the transverse waveguides for exciting multiple microwave modes in the heating chamber so as to achieve the goal of uniform microwave heating.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of and claims the prioritybenefit of U.S. application Ser. No. 14/983,600, filed on Dec. 30, 2015,now pending, which claims the priority benefit of Taiwan applicationserial no. 104136460, filed on Nov. 5, 2015. This application alsoclaims the priority benefit of Taiwan application serial no. 106133483,filed on Sep. 29, 2017. The entirety of each of the above-mentionedpatent applications is hereby incorporated by reference herein and madea part of this specification.

TECHNICAL FIELD

The disclosure is related to an operating method of microwave heatingdevice and a microwave annealing process using the method; moreparticularly, the disclosure is related to a coupling-mode operationmethod by adjusting the value of the capacitance of thehalf-wave-rectified power supply, such that the microwave power pulsebandwidth of the microwave transmitters are extended to produce aplurality of overlapped couplings, thereby multiplying microwave modenumbers so as to achieve uniform microwave heating.

BACKGROUND

Microwave heating technology has not only been applied in conventionalindustries (e.g., for dehydration of wood or brewers' yeast, forvulcanization of rubber, for thawing meat, and so on) but also beenapplied in semiconductor industries, e.g., for annealing silicon wafers.Semiconductor manufactural process contains hundreds of processes andeach of them poses impacts on the production capacity and the yield ofthe silicon wafers.

Here, the wafer annealing process is required to be performed after ionimplantation. When three-valance or five-valance elements are implantedinto a four-valance semiconductor, the issue of lattice defects islikely to arise, such that the properties of the semiconductor aredrastically changed; hence, the anneal step should be performed torecover the lattice structure, remove lattice defects, and move impurityatoms from an interstitial site to a substitution site through anneal,so as to activate electrical properties. Due to the issues forcontinuous shrink of interface thickness and line width in semiconductordevices, some types of anneal, such as infrared anneal orfar-ultraviolet laser anneal, have been facing the bottlenecks caused bythe issues aforesaid; however, microwave annealing process is notsubject to the aforementioned requirements.

However, the technical barrier of microwave anneal lies in the strictrequirement for anneal uniformity, i.e., high yield. The microwavefrequency adopted by the already commercialized microwave annealequipment is usually using 5.8 GHz or higher rather than 2.45 GHz (thecommon industrial microwave frequency). Shrink in wavelength ofcommercialized microwave anneal equipment leads to suppression ofstanding-wave effects and thus achieves uniform annealed results.However, compared to the 2.45 GHz magnetron, the 5.8 GHz magnetron hashigher costs but lower efficiency. Hence, a multi-mode microwave heating(annealing) device for microwave annealing process on silicon wafers orother to-be-heated objects is provided herein. The multi-mode microwaveheating (annealing) device usually uses (but not subject to use) thecommon industrial heating frequency of 2.45 GHz, which is sufficient toincrease the microwave heating efficiency and uniformity and furtherimproves the production capacity as well as the yield of theto-be-heated objects.

SUMMARY

The disclosure provides an operating method of microwave heating deviceand a microwave annealing process using the method, applying commonindustrial heating frequency of 2.45 GHz or other bands of frequency, iscapable of multiplying microwave mode numbers in the heating chamber,such that both efficient and uniform microwave heating is achieved.

In an embodiment of the disclosure, an operating method of microwaveheating device comprising the following steps. Provide a heating chamberhaving an accommodation space in which a holder disposed, and the holderhas a plane. Arrange a plurality of microwave transmitters outside theheating chamber to transmit microwave into the heating chamber. Providea plurality of half-wave-rectified power supplies to connect themicrowave transmitters, and the half-wave-rectified power supplies havecapacitances respectively. Install a plurality of longitudinalwaveguides and a plurality of transverse waveguides in between theheating chamber and the microwave transmitters, and the directions ofelectric field polarization of the longitudinal waveguides areperpendicular to the plane of the holder, and the directions of electricfield polarization of the transverse waveguides are parallel to theplane of the holder. Adjust the value of the capacitance ofhalf-wave-rectified power supply. Supply power to the microwavetransmitters by the half-wave-rectified power supplies so that themicrowaves are guided into the heating chamber by the longitudinalwaveguides and the transverse waveguides for exciting multiple microwavemodes in the heating chamber.

The disclosure further provide a microwave annealing process applying toa semiconductor device having dopant substance and a manufacturalprocess of a multi-mode microwave heating device, using commonindustrial heating frequency of 2.45 GHz or other bands of frequency,are capable of multiplying microwave mode numbers in the heatingchamber, such that both efficient and uniform microwave heating isachieved.

In an embodiment of the disclosure, a microwave annealing processapplying to a semiconductor device having dopant substance comprisingthe following steps. Provide a microwave heating device that includes aheating chamber arranged with an accommodation space in which a holderis disposed. The holder has a plane for holding the semiconductor devicehaving dopant substance. Adjust the value of the capacitance ofhalf-wave-rectified power supply. Supply power to the microwavetransmitters by the half-wave-rectified power supplies so that themicrowaves are guided into the heating chamber by the longitudinalwaveguides and the transverse waveguides for exciting multiple microwavemodes in the heating chamber, so as to apply microwave annealing processto the semiconductor device having dopant substance.

In an embodiment of the disclosure, a manufactural process of amulti-mode microwave heating device comprises the following steps.Provide a microwave heating device. Adjust the value of the capacitanceof half-wave-rectified power supply such that the microwave power pulsebandwidth of the microwave transmitters are extended to produce aplurality of overlapped couplings, thereby multiplying microwave modenumbers. Supply power to the microwave transmitters by thehalf-wave-rectified power supplies so that the microwaves are guidedinto the heating chamber by the longitudinal waveguides and thetransverse waveguides for exciting multiple microwave modes in theheating chamber.

In view of the above, by adjusting the value of the capacitance of thehalf-wave-rectified power supply such that the microwave power pulsebandwidth of the microwave transmitters are extended to produce aplurality of overlapped couplings, the operation method of thedisclosure produces multiplying microwave mode numbers; next, supplypower to the microwave transmitters by the half-wave-rectified powersupplies so that the microwaves are guided into the heating chamber bythe longitudinal waveguides and the transverse waveguides for excitingmultiple microwave modes in the heating chamber, so as to achieveuniform microwave heating.

Several exemplary embodiments accompanied with figures are described indetail below to further describe the disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide further understanding,and are incorporated in and constitute a part of this specification. Thedrawings illustrate exemplary embodiments and, together with thedescription, serve to explain the principles of the disclosure.

FIG. 1A-1 and FIG. 1A-2 are schematic views illustrating a multi-modemicrowave heating device according to a first embodiment of thedisclosure.

FIG. 1B-1, FIG. 1B-2, FIG. 1B-3, FIG. 1B-4, FIG. 1B-5 and FIG. 1B-6 areschematic views illustrating arrangement of a power circuit of themulti-mode microwave heating device according to the first embodiment ofthe disclosure.

FIG. 2A is a schematic view illustrating the way to excite alongitudinal-odd mode according to the first embodiment of thedisclosure.

FIG. 2B is a schematic view illustrating the way to excite alongitudinal-even mode according to the first embodiment of thedisclosure.

FIG. 2C is a schematic view illustrating the way to excite atransverse-odd mode according to the first embodiment of the disclosure.

FIG. 2D is a schematic view illustrating the way to excite atransverse-even mode according to the first embodiment of thedisclosure.

FIG. 2E is a schematic view illustrating the way to collectively excitethe longitudinal-odd mode and the longitudinal-even mode according tothe first embodiment of the disclosure.

FIG. 2F is a schematic view illustrating the way to collectively excitethe transverse-odd mode and the transverse-even mode according to thefirst embodiment of the disclosure.

FIG. 2G is a schematic view illustrating the way to collectively excitethe longitudinal-odd mode, the longitudinal-even mode, thetransverse-odd mode, and the transverse-even mode according to the firstembodiment of the disclosure.

FIG. 2H is a three-dimensional perspective view illustrating amulti-mode microwave heating device according to a second embodiment ofthe disclosure.

FIG. 3A is a schematic view illustrating a multi-mode microwave heatingdevice according to a third embodiment of the disclosure.

FIG. 3B is a schematic view illustrating a simulation result ofintensity distribution of a longitudinal electric field in FIG. 3A.

FIG. 3C schematically illustrates another implementation according tothe third embodiment of the disclosure.

FIG. 4 is a schematic view illustrating a multi-mode microwave heatingdevice according to the fourth embodiment of the disclosure.

FIG. 5 is a schematic diagram illustrating steps of an operating methodapplying to a microwave heating device according to the fifth embodimentof the disclosure.

FIG. 6 is a schematic diagram illustrating steps of a microwaveannealing process of a semiconductor device having dopant substanceaccording to the sixth embodiment of the disclosure.

DESCRIPTION OF THE EMBODIMENTS

A description accompanied with drawings is provided in the following tosufficiently explain embodiments of the disclosure. However, it is notedthat the disclosure may still be implemented in many other differentforms and should not be construed as limited to the embodimentsdescribed hereinafter. In the drawings, for the purpose of clarity andspecificity, the sizes and the relative sizes of each layer and regionmay not be illustrated in accurate proportion.

FIG. 1A-1 is a schematic view illustrating a multi-mode microwaveheating device according to a first embodiment of the disclosure. Withreference to FIG. 1A-1, the multi-mode microwave heating device 100 hassix longitudinal waveguides 151-156 and six transverse waveguides161-166 respectively connected between a heating chamber 110 and twelvemicrowave transmitters 131-142 for transmitting microwaves generated bythe microwave transmitters 131-142 to the inside of the heating chamber110 and exciting cavity modes in the heating chamber 110. The multi-modemicrowave heating device 100 has a holder 125 arranged in the heatingchamber 110 to hold a to-be-heated object 50. In the present embodiment,the holder 125 moves up and down and rotates through a rotating andelevating mechanism 120. The guided mode of the longitudinal waveguides151-156 is a rectangular TE₁₀ mode, and the direction of electric fieldin the longitudinal waveguides 151-156 is perpendicular to a plane (thex-y plane) of the holder 125. The guided mode of the transversewaveguides 161-166 is the rectangular TE₁₀ mode as well, but thedirection of the electric field in the transverse waveguides 161-166 isparallel to the plane of the holder 125. The directions of electricfield respectively in the longitudinal waveguides 151-156 and thetransverse waveguides 161-166 are perpendicular; hence, the cavity modesexcited by the six longitudinal waveguides 151-156 and the cavity modesexcited by the six transverse waveguides 161-166 are orthogonal.Besides, the junctions between the heating chamber 110 and the sixlongitudinal waveguides 151-156 are located at different positions ofthe heating chamber 110, and thus heights h₁, h₃, h₅, h₇, h₉, and h₁₁ ofthe six longitudinal waveguides 151-156 measured from the bottom surfaceof the heating chamber 110 are different. That is, h₁≠h₃≠h₅≠h₇≠h₉≠h₁₁.Therefore, in the present embodiment, as long as the heating chamber 110is large enough, the number of cavity modes in the heating chamber 110is sufficiently plenty, and the cavity modes respectively excited by thesix longitudinal waveguides 151-156 are different.

Similarly, the junctions between the heating chamber 110 and the sixtransverse waveguides 161-166 are located at different positions of theheating chamber 110, and thus heights h₂, h₄, h₆, h₈, h₁₀, and h₁₂ ofthe six transverse waveguides 161-166 measured from the bottom to thetop of the heating chamber 110 are different. That is,h₂≠h₄≠h₆≠h₈≠h₁₀≠h₁₂. As long as the number of cavity modes in theheating chamber 110 is plenty, the cavity modes respectively excited bythe six transverser waveguides 161-166 can be different. Hence,multi-modes can be excited according to the present embodiment, so as toachieve uniform heating. In the present embodiment, microwave deviceslike impedance matchers and isolators (not shown) are not required butmay be used in cases of: (1) reflected microwave powers aresignificantly high (in this case, isolators may be used to prevent thereflected microwave power back into the transmitters); (2) the cavitymodes excited by some of the waveguides 151-156 and 161-166 are the same(in this case, the impedance matchers may be used, in order to changethe input impedance of the waveguides 151-156 and 161-166 a little bitsuch that different cavity modes may be excited).

FIG. 1A-2 is another schematic view illustrating a multi-mode microwaveheating device according to the first embodiment of the disclosure. Withreference to FIG. 1A-2, the multi-mode microwave heating device 100 hassix longitudinal waveguides 151-156 and six transverse waveguides161-166 respectively installed in between the heating chamber 110 andmicrowave transmitters 131-142 for transmitting microwaves into theheating chamber 110 and exciting cavity modes of the heating chamber110. The multi-mode microwave heating device 100 has the holder 125arranged in the heating chamber 110 to hold the to-be-heated object 50.In the present embodiment, the holder 125 moves up and down and rotatesthrough the rotating and elevating mechanism 120. The guided mode of thelongitudinal waveguides 151-156 is the rectangular TE₁₀ mode, and thedirection of the electric field in the longitudinal waveguides 151-156is perpendicular to the plane (the x-y plane) of the holder 125. Theguided mode of the transverse waveguides 161-166 is the rectangular TE₁₀mode as well, but the direction of the electric field in the transversewaveguides 161-166 is parallel to the plane of the holder 125. Thedirections of the electric fields respectively in the longitudinalwaveguides 151-156 and the transverse waveguides 161-166 areperpendicular; hence, the cavity modes excited by the six longitudinalwaveguides 151-156 and the cavity modes excited by the transversewaveguides 161-166 are different and orthogonal. Besides, lengths L₃₁,L₃₃, L₃₅, L₃₇, L₃₉, and L₄₁ of the six longitudinal waveguides 151-156are different. That is, L₃₁≠L₃₃≠L₃₅≠L₃₇≠L₃₉≠L₄₁. Therefore, in thepresent embodiment, as long as the heating chamber 110 is large enough,the number of cavity modes in the heating chamber 110 is sufficientlyplenty, and the cavity modes excited by the six longitudinal waveguides151-156 are different.

Besides, lengths L₃₂, L₃₄, L₃₆, L₃₈, L₄₀, and L₄₂ of the six transversewaveguides 161-166 are different. That is, L₃≠L₃₄≠L₃₆≠L₃₈≠L₄₀≠L₄₂. Aslong as the number of cavity modes in the heating chamber 110 issufficient, the cavity modes respectively excited by the six transversewaveguides 161-166 can be different. Hence, twelve modes can be excitedaccording to the present embodiment, so as to achieve uniform heating.In the present embodiment, microwave devices such as impedance matchersand isolators (not shown) are not required but may be used in cases of:(1) reflected microwave powers are significantly high (in this case,isolators may be used to prevent the reflected microwave power fromreflecting back into the transmitters); (2) the cavity modes excited bysome of the waveguides 151-156 and 161-166 are the same (in this case,the impedance matchers may be used in order to change the inputimpedance of the waveguides 151-156 and 161-166 a little bit such thatdifferent cavity modes will be excited).

FIG. 1B-1, FIG. 1B-2, FIG. 1B-3, FIG. 1B-4, FIG. 1B-5 and FIG. 1B-6 areschematic views illustrating arrangement of a power circuit of themulti-mode microwave heating device according to the first embodiment ofthe disclosure. In one embodiment, the power circuit is arranged in themanner as shown in FIG. 1B-1, FIG. 1B-2, and FIG. 1B-3 to allow themicrowave transmitters 131-142 depicted in FIG. 1A-1 and FIG. 1A-2 totransmit pulsed microwave in a one-by-one time sequence control method(also known as serial mode control method) such that any two ofmagnetrons are decoupled. Besides, the power circuit provided herein canbe implemented using an industrial three-phase 60 (or 50) Hz alternatingcurrent (AC) power source 170 connecting in A (delta) type shown in FIG.1B-1. The A (delta) type AC power source 170 supplies time-domaindifferent-phased powers to half-wave-rectified microwave power supplies190 as shown in FIG. 1B-2. Likewise, the inverse-Y(wye)-connected ACpower sources 174 do the same thing as shown in FIG. 1B-3. Thehalf-wave-rectified power supplies 190 respectively offer pulsed powersto the microwave transmitters 131-142. Specifically, three connectingleads named R, S, and T of industrial three-phase AC power source 170offers three-phased powers named R-S, S-T, and T-R, of which phasesdiffer from one another by 120 degrees in time domain. Using half-waverectification, six-phased powers named R-S, S-T, T-R, S-R, T-S, and R-Tare generated, of which phases differ from one another by 60 degrees intime domain, such that the six-phased delta-connected power source 172is thus composed.

As shown in FIG. 1B-1, a common point C on the three-phase AC powersource 170 may be selected to generate three-phased powers named R-C,S-C, and T-C, and their time-domain phases differ from one another by120 degrees. Through half-wave rectification, six-phased power namedR-C, S-C, T-C, C-R, C-S, and C-T can be generated, and their time-domainphases differ from one another by 60 degrees, so as to constitute theinverse-wye-connected power source 174. Accordingly, using parallelconnection of the delta-connected power source 172 as well as theinverse-wye-connected power source 174 and half-wave rectification,twelve-phased powers named R-S, R-C, S-T, S-C, T-C, T-R, C-R, S-R, C-S,T-S, R-T, and C-T phased powers are generated, of which phases differfrom one another by 30 degrees in time domain. The twelve-phased powersnamed R-S, R-C, S-T, S-C, T-C, T-R, C-R, S-R, C-S, T-S, R-T, and C-T areshown in FIG. 1B-2 and FIG. 1B-3 and twelve half-wave-rectifiedmicrowave power supplies 190 provide the twelve-phased powers. As shownin FIG. 1B-4, each of the half-wave-rectified power supplies 190 has acapacitance 191 respectively. In one embodiment, the capacitance 191 iscomposed of a variable capacitance. By adjusting the value of thecapacitance 191 of at least one of the half-wave-rectified power supply190, the microwave power pulse bandwidth of the microwave transmitters131-142 are extended to produce a plurality of overlapped couplings,thereby multiplying microwave mode numbers. FIG. 1B-5 is schematicdiagram illustrating an operating method combining serial mode controland coupling mode control according to an embodiment of the disclosure.

In particular, after adjusting the value of the capacitance 191, thetwelve half-wave-rectified power supplies 190 supply powers to thetwelve microwave transmitters 131-142 respectively, such that microwavetransmitters 131-142 transmit pulsed microwave in a one-by-one timesequence control method (also known as serial mode control method).Therefore, 24 more mode numbers are produced by the twelve waveguides,as shown in FIG. 1B-4, such that the microwave mode numbers become 36totally after multiplying, finally 72 mode numbers are produced by thetwelve microwave transmitters. By increasing the mode numberssignificantly, coupling mode control can multiply microwave heatinguniformity and efficiency than serial mode control.

Besides, the twelve microwave transmitters 131-142 are powered such thatthe microwave powers are transmitted by the one-by-one time sequencecontrol method (serial mode control method), while only a singlemicrowave transmitter transmits the microwave power at one time.Therefore, no interference would occur between the microwavetransmitters 131-142, and no mode lock would happen between magnetrons.In this way, the efficiency of the microwave transmitters 131-142 wouldnot decrease. Meanwhile, as long as all of the waveguides 151-156 and161-166, which corresponds to each of the microwave transmitters 131-142respectively, excite the cavity modes in the heating chamber 110, thereflected power back into the microwave transmitters 131-142 is low evenwithout isolators being installed. Thus, the efficiency of the microwavetransmitters 131-142 would not decrease. In addition, since no isolatorshas to be installed in this embodiment, the power loss may be excluded,thereby improving the heating efficiency of the multi-mode microwaveheating device 100.

In another embodiment, as shown in FIG. 1B-6, adjust the value of thecapacitance 191 of the half-wave-rectified power supply 190 such thatthe microwave power pulse bandwidth of the microwave transmitters131-142 are extended to produce much more overlapped couplings, therebythe microwave mode numbers become 60 due to 48 plus 12. Finally, 120mode numbers are produced by the twenty four microwave transmitters.

FIG. 2A is a schematic view illustrating the way to excite alongitudinal-odd mode according to the first embodiment of thedisclosure. Microwave power is transmitted by the first microwavetransmitter 131, further divided by an in-phase equal-power divider andthen fed into the heating chamber 110 through two equal-lengthlongitudinal waveguides 151 a. The junctions between the waveguides 151a and the heating chamber 110 are defined as the microwave input portsand denoted by thin arrows named 111 a and 111 b, as shown in FIG. 2A. A180-degree phase shifter 185 is installed in between the input port 111b and the in-phase equal-power divider 180. Hence, the phase of thelongitudinal electric field arriving at the input port 111 a differsfrom the phase of the longitudinal electric field arriving at the inputport 111 b by 180 degrees (the polarization directions of thelongitudinal electric fields are respectively denoted by ⊙ and ⊕, so asto represent that the polarization directions of the longitudinalelectric fields are perpendicular to the x-y plane, and the phases ofthe longitudinal electric fields differ from each other by 180 degrees).Destructive interference thus occurs on a central line (the x axis) ofthe heating chamber 110, which is referred to as a longitudinal-oddmode. After simulation, the intensity distribution of electric field isidentified as a longitudinal-even mode as shown by the image on theright-hand side of FIG. 2B. In the present embodiment, the impedancematcher (not shown) is not required unless the reflected power back intothe microwave transmitter 131 is significantly high; in this case, theimpedance matcher may be installed between the microwave transmitter 131and the in-phase equal-power divider 180, so as to reduce the reflectedpower.

FIG. 2B is a schematic view illustrating the way to excite alongitudinal-even mode according to the first embodiment of thedisclosure. Here, microwave power is transmitted by the first microwavetransmitter 133, then divided by an in-phase equal-power divider andthen fed into the heating chamber 110 through two equal-lengthlongitudinal waveguides 152 a. The junctions between the longitudinalwaveguides 152 a and the heating chamber 110 are defined as themicrowave input ports and denoted by thin arrows named 112 a and 112 b,as shown in FIG. 2A. As long as the two longitudinal waveguides 152 ahave the same length, the phase of the longitudinal electric fieldarriving at the input port 112 a is the same as the phase of thelongitudinal electric field arriving at the input port 112 b (thepolarization directions of the longitudinal electric field are bothdenoted by ⊙). Constructive interference thus occurs on a central line(the y axis) of the heating chamber 110, which is referred to as alongitudinal-even mode. After simulation, the result of electric fieldintensity distribution is identified as a longitudinal-even mode forsure as shown on the right-hand side of FIG. 2B. In the presentembodiment, the impedance matcher (not shown) is not required but may beused when the reflected power significantly high; in this case, theimpedance matcher may be installed between the microwave transmitter 133and the in-phase equal-power divider 180, so as to reduce the reflectedpower.

FIG. 2C is a schematic view illustrating the way to excite atransverse-odd mode according to the first embodiment of the disclosure.Here, microwave power is transmitted by the second microwave transmitter132, further divided by an in-phase equal-power divider 180 and then fedinto the heating chamber 110 through two equal-length transversewaveguides 161 a. The junctions between the transverse waveguides 161 aand the heating chamber 110 are defined as the microwave input ports andare denoted by thin arrows and named 113 a and 113 b. The 180-degreephase shifter 185 may be assembled in between the input port 113 b andthe in-phase equal-power divider 180, whereas no 180-degree phaseshifter 185 is installed in between the input port 113 a and thein-phase equal-power divider 180. Hence, the phase of the transverseelectric field arriving at the input port 113 a differs from the phaseof the transverse electric field arriving at the input port 113 b by 180degrees (the polarization directions of the transverse electric fieldsare respectively marked by thick arrows in FIG. 2C, the oppositedirections of the arrows indicate the 180-degree difference in phase,and the two opposite directions are both parallel to the x′-y′ plane).Destructive interference thus occurs on a central line (the z axis) ofthe heating chamber 110, which is referred to as a transverse-odd mode.After simulation, the intensity distribution of the transverse electricfield in the transverse-odd mode is shown on the right-hand side of FIG.2C. In the present embodiment, the impedance matcher (not shown) is notrequired unless the reflected power back into the microwave transmitter132 is significant; in this case, the impedance matcher may be installedin between the microwave transmitter 132 and the in-phase equal-powerdivider 180, so as to reduce the reflected power.

FIG. 2D is a schematic view illustrating the way to excite atransverse-even mode according to the first embodiment of thedisclosure. The fourth microwave transmitter 134 may transmit themicrowave into the heating chamber 110 through the in-phase equal-powerdivider 180 and two transverse waveguides 162 a. The junctions betweenthe waveguides 162 a and the heating chamber 110 are defined as themicrowave input ports and are denoted by thin arrows and named 114 a and114 b. As long as the two transverse waveguides 162 a have the samelength, the phase of the transverse electric field arriving at the inputport 114 a is the same as the phase of the transverse electric fieldarriving at the input port 114 b (the polarization directions of thetransverse electric fields are both marked by thick arrows in FIG. 2D).Constructive interference thus occurs on a central line (the z axis) ofthe heating chamber 110, which is referred to as a transverse-even mode.After simulation, result of the intensity distribution of the transverseelectric field is identified as a transverse-even mode for sure as shownon the right-hand side of FIG. 2D. In the present embodiment, theimpedance matcher (not shown) is not required unless when the reflectedpower back into by the microwave transmitter 134 is significant; in thiscase, the impedance matcher may be assembled in between the microwavetransmitter 134 and the in-phase equal-power divider 180, so as toreduce the reflected power.

FIG. 2E is a schematic view illustrating the way to collectively excitethe longitudinal-odd mode and the longitudinal-even mode according tothe first embodiment of the disclosure. As shown in FIG. 2E, thelongitudinal-odd mode shown in FIG. 2A and the longitudinal-even modeshown in FIG. 2B are combined in the present embodiment. For instance,the two input ports 111 a and 111 b in the longitudinal-odd mode are onthe y axis in FIG. 2E; besides, the two input ports 112 a and 112 b inthe longitudinal-even mode are on the x axis. The longitudinal-odd modeand the longitudinal-even mode are orthogonal modes, which are conservedby the symmetry in the x direction and the y direction.

FIG. 2F is a schematic view illustrating the way to collectively excitethe transverse-odd mode and the transverse-even mode according to thefirst embodiment of the disclosure. As shown in FIG. 2F, thetransverse-odd mode shown in FIG. 2C and the transverse-even mode shownin FIG. 2D are combined in the present embodiment. For instance, the twoinput ports 113 a and 113 b in the transverse odd mode are on the y′axis in FIG. 2F; besides, the two input ports 114 a and 114 b in thetransverse-even mode are on the x′ axis. The transverse-odd mode and thetransverse even mode are orthogonal and are conserved by the symmetry inthe x′ direction and the y′ direction. Additionally, the longitudinalmode and the transverse mode are also orthogonal and are conserved bythe symmetry in the x direction and the y direction. In the presentembodiment, the coordinate x′y′ is obtained by rotating the coordinatexy by 45 degrees around the z axis.

FIG. 2G is a schematic view illustrating the way to collectively excitethe longitudinal-odd mode, the longitudinal-even mode, thetransverse-odd mode, and the transverse-even mode according to the firstembodiment of the disclosure. In the present embodiment, the respectiveinput ports in the longitudinal-odd mode, the longitudinal-even mode,the transverse-odd mode, and the transverse-even mode are 111 a, 111 b,112 a, 112 b, 113 a, 113 b, 114 a, and 114 b. For illustrative purposes,FIG. 2G merely shows the eight input ports mentioned above and thepolarization directions of the electric fields but does not show thefour microwave transmitters corresponding to the eight input ports.

FIG. 2H is a three-dimensional perspective view illustrating amulti-mode microwave heating device according to a second embodiment ofthe disclosure. In FIG. 2H, the thin arrow indicates the direction wherethe microwave is input, and the thick arrow indicates the polarizationdirection of the electric field. The ways to excite three groups of thelongitudinal-odd mode, the longitudinal-even mode, the transverse-oddmode, and the transverse-even mode are incorporated in the multi-modemicrowave heating device 200. In the first group, the respective inputports in the longitudinal-odd mode, the longitudinal-even mode, thetransverse-odd mode, and the transverse-even mode are 201 a, 201 b, 202a, 202 b, 203 a, 203 b, 204 a, and 204 b. The aforesaid input ports 201a, 201 b, 202 a, 202 b, 203 a, 203 b, 204 a, and 204 b input microwavesrespectively through the middle section of the heating chamber 210. Inthe second group, the respective input ports in the longitudinal-oddmode, the longitudinal-even mode, the transverse-odd mode, and thetransverse-even mode are 205 a, 205 b, 206 a, 206 b, 207 a, 207 b, 208a, and 208 b. The aforesaid input ports 205 a, 205 b, 206 a, 206 b, 207a, 207 b, 208 a, and 208 b respectively input microwaves respectivelythrough the upper section of the heating chamber 210. In the thirdgroup, the respective input ports in the longitudinal-odd mode, thelongitudinal-even mode, the transverse-odd mode, and the transverse-evenmode are 209 a, 209 b, 210 a, 210 b, 211 a, 211 b, 212 a, and 212 b. Theaforesaid input ports 209 a, 209 b, 210 a, 210 b, 211 a, 211 b, 212 a,and 212 b input microwaves respectively through the lower section of theheating chamber 210. For illustrative purposes, FIG. 2H merely shows thetwenty-four input ports mentioned above and the polarization directionsof the electric fields but does not show the twelve microwavetransmitters corresponding to the twenty-four input ports.

The arrangement of the power circuit provided in the present embodimentis the same as that provided in the first embodiment and shown in FIG.1B-1. Therefore, the twelve microwave transmitters provided hereintransmit the microwaves one by one according to a time sequence controlmethod. Within one period of time, only one of the microwavetransmitters transmits microwaves. Therefore, no interference wouldoccur between the microwave transmitters, and no mode lock would happenbetween magnetrons. As long as the microwave transmitters excite thecavity modes in the heating chamber 210, the reflected power back intothe transmitters is low even without isolators being installed. Becauseof that, power loss absorbed by isolators is excluded, and the heatingefficiency as well as heating uniformity of the multi-mode microwaveheating device 200 can be improved.

FIG. 3A is a schematic view illustrating a multi-mode microwave heatingdevice according to a third embodiment of the disclosure. Six microwavetransmitters 331-336 are spaced from each other by 60 degrees forconnecting to heating chamber 310 through six longitudinal waveguides351-356, of which lengths L₁, L₂, L₃, L₄, L₅, and L₆ are different, andsatisfy the constraint that L₆−L₅=L₅−L₄=L₄ L₃=L₃ L₂=L₂−L₁=λ_(g)/12. Thelength difference between the adjacent waveguides 351-356 is one twelfthof the guided wavelength λ_(g), such that the input impedances Z_(in1),Z_(in3), Z_(in3), Z_(in4), Z_(in5), and Z_(in6) at the junctions(defined as the input ports) between each of the microwave transmitters331-336 are different. That is,Z_(in1)≠Z_(in2)≠Z_(in3)≠Z_(in4)≠Z_(in5)≠Z_(in6), and the frequencypulling effects achieved by each of the microwave transmitters 331-336are not the same. In the present embodiment, as long as the size of theheating chamber 310 is large enough, the number of the cavity modes isplenty; as such, the microwave transmitters 331-336 with differentlyslight-pulled frequencies are capable of exciting different cavity modesto achieve uniform heating.

FIG. 3B is a schematic view illustrating a simulation result ofintensity distribution of a longitudinal electric field depicted in FIG.3A. When one of the six microwave transmitters 331-336 transmits themicrowave, the other five microwave transmitters is not in operation;hence, microwave is transmitted from one transmitter at a time, and theother five transmitters are temporarily idle, as shown in FIG. 3B.According to the simulation as shown in FIG. 3B, the microwavetransmitters 331-336 with differently slight-pulled frequencies arecapable of exciting different cavity modes to achieve uniform heating.

In the present embodiment, the arrangement of powers can be similar tothat provided in the first embodiment and shown in FIG. 1B-1, i.e., theindustrial three-phase AC power source 170 supplies power to sixhalf-wave-rectified power supplies 190 through the delta-connected powersource 172 or the inverse-wye-connected power source 174, and the sixhalf-wave-rectified power supplies 190 then offer powers to sixmicrowave transmitters 331-336.

FIG. 3C schematically illustrates another implementation according tothe third embodiment of the disclosure. In the present embodiment,microwave transmissions of the twelve microwave transmitters 431-442 arephase-delayed from each other by 30 degrees in time domain. Lengths L₁₂,L₁₄, L₁₆, L₁₈, L₂₀, and L₂₂ of the six longitudinal waveguides 451-456are different and satisfy the following condition thatL₂₂−L₂₀=L₂₀−L₁₈=L₁₈−L₁₆=L₁₆−L₁₄=L₁₄−L₁₂==λ_(g)/12. The length differencebetween the adjacent waveguides 451-456 is set to be one twelfth of theguided wavelength λ_(g), such that the input impedances Z_(in12),Z_(in14), Z_(in16), Z_(in18), Z_(in20), and Z_(in22) at the junctions(defined as the input ports) are different, i.e.,Z_(in12)≠Z_(in14)≠Z_(in16)≠Z_(in18)≠Z_(in20)≠Z_(in22). Thereby, thefrequency pulling effects of the microwave transmitters 432, 434, 436,438, 440, and 442 are different.

Similarly, lengths L₁₁, L₁₃, L₁₅, L₁₇, L₁₉, and L₂₁ of the sixtransverse waveguides 461-466 are different and satisfy the followingcondition that L₂₁−L₁₉=L₁₉−L₁₇=L₁₇−L₁₅=L₁₅−L₁₃=L₁₃−L₁₁=λ_(g)/12. Thatis, the length difference between the adjacent waveguides 461-466 is onetwelfth of the wavelength λ_(g), such that the input impedancesZ_(in11), Z_(in13), Z_(in15), Z_(in17), Z_(in19), and Z_(in21) at thejunctions (defined as the input ports) are different, i.e.,Z_(in11)≠Z_(in13)≠Z_(in13)≠Z_(in15)≠Z_(in17)≠Z_(in19)≠Z_(in21). Thereby,the frequency pulling effects of the microwave transmitters 431, 433,435, 437, 439, and 441 are different. In the present embodiment, as longas the size of the heating chamber 410 is large enough, the number ofthe cavity modes is plenty; as such, the microwave transmitters 431-442with differently slight-pulled frequencies are capable of excitingdifferent cavity modes to achieve uniform heating.

In the present embodiment, the arrangement of powers can be the same asthat provided in the first embodiment and shown in FIG. 1B-1, i.e., theindustrial three-phase AC power source 170 offers powers to the twelvehalf-wave-rectified power supplies (not shown) using a delta-connectedpower source 172 combined with an inverse-wye-connected power source174, by which the twelve microwave transmitters 431-442 are powered.

FIG. 4 is a schematic view illustrating a multi-mode microwave heatingdevice according to a fourth embodiment of the disclosure. In themulti-mode microwave heating device 500 provided in the presentembodiment, a transport belt 575 is continuously driven by rolls 570 ina roll-to-roll manner, so as to transport the to-be-heated object 50 ina direction shown by the arrow in FIG. 4. The multi-mode microwaveheating device 500 can be equipped with multiple heating chambers (FIG.4 exemplarily shows three heating chambers 511, 512, and 513) as well asmultiple microwave transmitters (FIG. 4 exemplarily shows three groupsof microwave transmitters 531, 532, and 533). The three groups ofmicrowave transmitters respectively have multiple microwave transmitters1-12, l′-12′, and 1″-12″, and each group of microwave transmitterscorresponds to multiple longitudinal waveguides and multiple transversewaveguides (not shown). In the present embodiment, the connection mannerbetween each group of waveguides and the heating chambers 511, 512, and513 may be referred to as those provided in the previous embodiments andmay be implemented according to any of the previous embodiments.Besides, low-pass filters 580 may be arranged at inlets and outlets ofthe heating chambers 511, 512, and 513, as well as between the heatingchambers 511, 512, and 513, such that microwave leakages from chambersand cross couples between chambers are excluded.

In the present embodiment, the arrangement of power can be similar tothat provided in the first embodiment and shown in FIG. 1B-1, i.e., theindustrial three-phase AC power source 170 supplies power to twelvehalf-wave-rectified power supplies in each group through thedelta-connected power source 172 or the inverse-wye-connected powersource 174, and the twelve half-wave-rectified power supplies thensupply power to each group of twelve microwave transmitters 1-12,1′-12′, and 1″-12″. The low-pass filters 580 serve to block interferenceof microwaves among the heating chambers 511, 512, and 513; hence, nointerference (couple) would occur between each group of microwavetransmitters, and no mode lock would happen; and the efficiency of eachmicrowave transmitter and the diversity of the cavity modes can beguaranteed.

FIG. 5 is a schematic diagram of the sequence illustrating steps of anoperating method microwave applying to a microwave heating deviceaccording to the fifth embodiment of the disclosure.

In step S101, dispose a holder in an accommodation space of a heatingchamber, and the holder has a plane for holding a to-be-heated object.

In step S102, arrange a plurality of microwave transmitters outside theheating chamber to transmit microwave.

In step S103, provide a plurality of half-wave-rectified power suppliesto connect the microwave transmitters, and the half-wave-rectified powersupplies have capacitances respectively. The capacitance is composed ofa variable capacitance. The quantity of the half-wave-rectified powersupply and the operation method can be reference to above embodiments.

In step S104, install a plurality of longitudinal waveguides and aplurality of transverse waveguides in between the heating chamber andthe microwave transmitters, and the directions of electric fieldpolarization of the longitudinal waveguides are perpendicular to theplane of the holder, and the directions of electric field polarizationof the transverse waveguides are parallel to the plane of the holder.The arrangement of longitudinal waveguides and transverse waveguides canbe reference to above embodiments.

In step S105, adjust the value of the capacitance of each of thehalf-wave-rectified power supplies, such that the microwave power pulsebandwidth of the microwave transmitters are extended to produce aplurality of overlapped couplings, thereby multiply microwave modenumbers.

In step S106, supply power to the microwave transmitters by thehalf-wave-rectified power supplies so that the microwaves are guidedinto the heating chamber by the longitudinal waveguides and thetransverse waveguides for exciting multiple microwave modes in theheating chamber, so as to apply microwave heating to the to-be-heatedobject.

FIG. 6 is a schematic diagram of the sequence illustrating steps of amicrowave annealing process microwave according to the sixth embodimentof the disclosure.

In step S201, provide a microwave heating device as described above to asemiconductor device having dopant substance.

In step S202, adjust the value of the capacitance of thehalf-wave-rectified power supply of the microwave heating device, suchthat the microwave power pulse bandwidth of the microwave transmittersconnected respectively are extended to produce a plurality of overlappedcouplings, thereby multiply microwave mode numbers.

In step S203, supply power to the microwave transmitters by thehalf-wave-rectified power supplies so that the microwaves are guidedinto the heating chamber by the longitudinal waveguides and thetransverse waveguides for exciting multiple microwave modes in theheating chamber. Then, apply microwave annealing process to thesemiconductor device having dopant substance.

An experiment is provided in the following for illustrating the effectof the present embodiment. However, it is noted that the disclosure maystill be implemented in many other different forms and should not beconstrued as limited to the experiment described hereinafter.

Experiment I: Comparison of operation method 1 (microwave annealingprocesses without coupling-mode operation method) and operation method 2(microwave annealing processes with applying coupling-mode operationmethod) is made. In the present experiment, operation method 1 and 2 ofmicrowave annealing processes apply to 12″ wafer having dopant As usingmicrowave heating frequency 2.45 GHz. Refer to Table A, operation method1 is sequence control method (serial mode control), and the microwavetransmitters transmit pulsed microwave in a one-by-one time sequence.Operation method 2 combines serial mode control and coupling modecontrol, and the microwave power pulse bandwidth of the microwavetransmitters are extended to produce a plurality of overlappedcouplings, thereby multiply microwave mode numbers. As shown in Table A,by method 2, annealing time is reduced about 20%, sheet resistance isreduced about 2.5% and the heating ununiformity is reduced about 80%than by method 1.

TABLE A semiconductor device having dopant substance: 12″ wafer havingoperation method 1 operation method 2 dopant As (without coupling) (withcoupling) annealing time (sec.) 600 480 Ω/□ (sheet resistance) 147.3143.6 ununiformity (%) 4.1 0.8

To sum up, in the present disclosure, the microwave transmitters areconnected to the heating chamber through the longitudinal waveguides andtransverse waveguides for guiding microwaves to the inside of theheating chamber and exciting multiple cavity modes in the heatingchamber, so as to achieve uniform microwave heating. The three-phase ACpower source supplies power to the half-wave-rectified power supplies,and the half-wave-rectified power supplies respectively power themicrowave transmitters. Through adjusting (increasing) the value of thecapacitance of the half-wave-rectified power supply such that themicrowave power pulse bandwidth of the microwave transmitters areextended to produce a plurality of overlapped couplings, therebymultiply microwave mode numbers. The more the microwave mode number are,the better microwave heating uniformity is. The microwave heatingefficiency and uniformity of the annealing process applying tosemiconductor device having dopant substance are also improved.

It will be apparent to those skilled in the art that variousmodifications and variations can be made to the structure of thedisclosed embodiments without departing from the scope or spirit of thedisclosure. In view of the foregoing, it is intended that the disclosurecover modifications and variations of this disclosure provided they fallwithin the scope of the following claims and their equivalents.

What is claimed is:
 1. An operating method of microwave heating device comprising: providing a heating chamber having an accommodation space in which a holder is disposed, and the holder has a plane; arranging a plurality of microwave transmitters outside the heating chamber to transmit microwave into the heating chamber; providing a plurality of half-wave-rectified power supplies to connect the microwave transmitters, and each of the half-wave-rectified power supplies has a capacitance respectively; installing a plurality of longitudinal waveguides and a plurality of transverse waveguides in between the heating chamber and the microwave transmitters, and the directions of electric field polarization of the longitudinal waveguides are perpendicular to the plane of the holder, and the directions of electric field polarization of the transverse waveguides are parallel to the plane of the holder; adjusting the value of the capacitance of at least one of the half-wave-rectified power supplies, such that the microwave power pulse bandwidth of the microwave transmitters are extended to produce a plurality of overlapped couplings; and supplying power to the microwave transmitters by the half-wave-rectified power supplies so that the microwaves are guided into the heating chamber by the longitudinal waveguides and the transverse waveguides for exciting multiple microwave modes in the heating chamber.
 2. The operating method of microwave heating device of claim 1, wherein the longitudinal waveguides are divided into two sets with equal power, and the two divided sets are installed symmetrically connected to the heating chamber, such that the microwaves with out-of-phase electric fields are symmetrically guided into the heating chamber to excite multiple longitudinal-odd modes.
 3. The operating method of microwave heating device of claim 1, wherein the longitudinal waveguides are divided into two sets with equal power, and the two sets are installed symmetrically connected to the heating chamber, such that the microwaves with in-phase electric fields are symmetrically guided into the heating chamber to excite multiple longitudinal-even modes.
 4. The operating method of microwave heating device of claim 1, wherein the transverse waveguides are divided into two sets with equal power, and the two sets are installed symmetrically connected to the heating chamber, such that microwaves with out-of-phase electric fields are symmetrically guided into the heating chamber to excite multiple transverse-odd modes.
 5. The operating method of microwave heating device of claim 1, wherein the transverse waveguides are divided into two sets with equal power, and the two sets are installed symmetrically connected to the heating chamber, such that microwaves with in-phase electric fields are symmetrically guided into the heating chamber to excite multiple transverse-even modes.
 6. The operating method of microwave heating device of claim 1, wherein the longitudinal waveguides are spaced from each other by a fixed angle and installed in between the heating chamber and the corresponding microwave transmitters to excite the multiple longitudinal modes, a difference in length of the adjacent waveguides is set to be a one-half guided wavelength divided by the number of the corresponding longitudinal waveguides.
 7. The operating method of microwave heating device of claim 1, wherein the transverse waveguides are spaced from each other by a fixed angle and installed in between the heating chamber and the corresponding microwave transmitters to excite the multiple transverse modes, a difference in length of the adjacent waveguides is set to be a one-half guided wavelength divided by the number of the corresponding transverse waveguides.
 8. The operating method of microwave heating device of claim 1, wherein the half-wave-rectified power supplies are twelve, and before the step of adjusting the value of the capacitance, the half-wave-rectified power supplies are powered by an industrial three-phase alternate-current power source having three connecting leads named R, S, and T, and connecting the three connecting leads in a delta type to generate six-phased powers named R-S, S-T, T-R, S-R, T-S, and R-T providing to six of the half-wave-rectified power supplies.
 9. The operating method of microwave heating device of claim 8, wherein before the step of adjusting the value of the capacitance, the half-wave-rectified power supplies are powered by an industrial three-phase alternate-current power source having three connecting leads named R, S, and T, and connecting the three connecting leads to a common-point C on the three-phase AC power source i in an inverse-wye type to generate six-phased powers named R-C, S-C, T-C, C-R, C-S, and C-T providing to another six of the half-wave-rectified power supplies.
 10. The operating method of microwave heating device of claim 1, wherein the half-wave-rectified power supplies are twelve, and before the step of adjusting the value of the capacitance, the half-wave-rectified power supplies are powered by an industrial three-phase alternate-current power source connected in a delta type as well as in an inverse-wye type to generate twelve-phased powers named R-S, R-C, S-T, S-C, T-C, T-R, C-R, S-R, C-S, T-S, R-T, C-T providing to twelve of the half-wave-rectified power supplies.
 11. The operating method of microwave heating device of claim 1, wherein the capacitance is composed of a variable capacitance.
 12. A microwave annealing process applying to a semiconductor device having dopant substance comprising: providing a microwave heating device including: a heating chamber arranged having an accommodation space in which a holder is disposed, and the holder has a plane for holding the semiconductor device having dopant substance; a plurality of microwave transmitters arranged outside the heating chamber to transmit microwaves into the heating chamber; a plurality of half-wave-rectified power supplies arranged to connect the microwave transmitters, and each of the half-wave-rectified power supplies has a capacitance respectively; and a plurality of longitudinal waveguides and a plurality of transverse waveguides installed in between the heating chamber and the microwave transmitters, wherein the directions of electric field polarization of the longitudinal waveguides are perpendicular to the plane of the holder, and the directions of electric field polarization of the transverse waveguides are parallel to the plane of the holder; adjusting the value of the capacitance of at least one of the half-wave-rectified power supplies, such that the microwave power pulse bandwidth of the microwave transmitters are extended to produce a plurality of overlapped couplings, thereby multiplying microwave mode numbers; and supplying power to the microwave transmitters by the half-wave-rectified power supplies so that the microwaves are guided into the heating chamber by the longitudinal waveguides and the transverse waveguides for exciting multiple microwave modes in the heating chamber; and applying microwave annealing process to the semiconductor device having dopant substance.
 13. A manufactural process of a multi-mode microwave heating device comprising: providing a microwave heating device including: a heating chamber arranged having an accommodation space in which a holder is disposed, and the holder has a plane; a plurality of microwave transmitters arranged outside the heating chamber to transmit microwaves into the heating chamber; a plurality of half-wave-rectified power supplies arranged to connect the microwave transmitters, and the half-wave-rectified power supplies have capacitances; and a plurality of longitudinal waveguides and a plurality of transverse waveguides installed in between the heating chamber and the microwave transmitters, wherein the directions of electric field polarization of the longitudinal waveguides are perpendicular to the plane of the holder, and the directions of electric field polarization of the transverse waveguides are parallel to the plane of the holder; adjusting the value of the capacitance of at least one of the half-wave-rectified power supplies, such that the microwave power pulse bandwidth of the microwave transmitters are extended to produce a plurality of overlapped couplings, thereby multiplying microwave mode numbers; and supplying power to the microwave transmitters by the half-wave-rectified power supplies so that the microwaves are guided into the heating chamber by the longitudinal waveguides and the transverse waveguides for exciting multiple microwave modes in the heating chamber.
 14. A process of claim 12 wherein the longitudinal waveguides are divided into two sets with equal power, and the two divided sets are installed symmetrically connected to the heating chamber, such that the microwaves with out-of-phase electric fields are symmetrically guided into the heating chamber to excite multiple longitudinal-odd modes.
 15. A process of claim 12, wherein the longitudinal waveguides are divided into two sets with equal power, and the two sets are installed symmetrically connected to the heating chamber, such that the microwaves with in-phase electric fields are symmetrically guided into the heating chamber to excite multiple longitudinal-even modes.
 16. A process of claim 12, wherein the transverse waveguides are divided into two sets with equal power, and the two sets are installed symmetrically connected to the heating chamber, such that microwaves with out-of-phase electric fields are symmetrically guided into the heating chamber to excite multiple transverse-odd modes.
 17. A process of claim 12, wherein the transverse waveguides are divided into two sets with equal power, and the two sets are installed symmetrically connected to the heating chamber, such that microwaves with in-phase electric fields are symmetrically guided into the heating chamber to excite multiple transverse-even modes.
 18. A process of claim 12, wherein the longitudinal waveguides are spaced from each other by a fixed angle and installed in between the heating chamber and the corresponding microwave transmitters to excite the multiple longitudinal modes, a difference in length of the adjacent waveguides is set to be a one-half guided wavelength divided by the number of the corresponding longitudinal waveguides, and wherein the transverse waveguides are spaced from each other by a fixed angle and installed in between the heating chamber and the corresponding microwave transmitters to excite the multiple transverse modes, a difference in length of the adjacent waveguides is set to be a one-half guided wavelength divided by the number of the corresponding longitudinal waveguides.
 19. A process of claim 12, wherein the half-wave-rectified power supplies are twelve, and before the step of adjusting the value of the capacitance, the half-wave-rectified power supplies are powered by an industrial three-phase alternate-current power source having three connecting leads named R, S, and T, and connecting the three connecting leads in a delta type to generate six-phased powers named R-S, S-T, T-R, S-R, T-S, and R-T providing to six of the half-wave-rectified power supplies, and wherein the half-wave-rectified power supplies are powered by an industrial three-phase alternate-current power source having three connecting leads named R, S, and T, and connecting the three connecting leads to a common-point C on the three-phase AC power source i in an inverse-wye type to generate six-phased powers named R-C, S-C, T-C, C-R, C-S, and C-T providing to another six of the half-wave-rectified power supplies.
 20. A process of claim 12, wherein the half-wave-rectified power supplies are twelve, and before the step of adjusting the value of the capacitance, the half-wave-rectified power supplies are powered by an industrial three-phase alternate-current power source connected in a delta type as well as in an inverse-wye type to generate twelve-phased powers named R-S, R-C, S-T, S-C, T-C, T-R, C-R, S-R, C-S, T-S, R-T, C-T providing to twelve of the half-wave-rectified power supplies.
 21. A process of claim 12, wherein each of the capacitance is composed of a variable capacitance.
 22. A process of claim 13, wherein the longitudinal waveguides are divided into two sets with equal power, and the two divided sets are installed symmetrically connected to the heating chamber, such that the microwaves with out-of-phase electric fields are symmetrically guided into the heating chamber to excite multiple longitudinal-odd modes.
 23. A process of claim 13, wherein the longitudinal waveguides are divided into two sets with equal power, and the two sets are installed symmetrically connected to the heating chamber, such that the microwaves with in-phase electric fields are symmetrically guided into the heating chamber to excite multiple longitudinal-even modes.
 24. A process of claim 13, wherein the transverse waveguides are divided into two sets with equal power, and the two sets are installed symmetrically connected to the heating chamber, such that microwaves with out-of-phase electric fields are symmetrically guided into the heating chamber to excite multiple transverse-odd modes.
 25. A process of claim 13, wherein the transverse waveguides are divided into two sets with equal power, and the two sets are installed symmetrically connected to the heating chamber, such that microwaves with in-phase electric fields are symmetrically guided into the heating chamber to excite multiple transverse-even modes.
 26. A process of claim 13, wherein the longitudinal waveguides are spaced from each other by a fixed angle and installed in between the heating chamber and the corresponding microwave transmitters to excite the multiple longitudinal modes, a difference in length of the adjacent waveguides is set to be a one-half guided wavelength divided by the number of the corresponding longitudinal waveguides, and wherein the transverse waveguides are spaced from each other by a fixed angle and installed in between the heating chamber and the corresponding microwave transmitters to excite the multiple transverse modes, a difference in length of the adjacent waveguides is set to be a one-half guided wavelength divided by the number of the corresponding longitudinal waveguides.
 27. A process of claim 13, wherein the half-wave-rectified power supplies are twelve, and before the step of adjusting the value of the capacitance, the half-wave-rectified power supplies are powered by an industrial three-phase alternate-current power source having three connecting leads named R, S, and T, and connecting the three connecting leads in a delta type to generate six-phased powers named R-S, S-T, T-R, S-R, T-S, and R-T providing to six of the half-wave-rectified power supplies, and wherein the half-wave-rectified power supplies are powered by an industrial three-phase alternate-current power source having three connecting leads named R, S, and T, and connecting the three connecting leads to a common-point C on the three-phase AC power source i in an inverse-wye type to generate six-phased powers named R-C, S-C, T-C, C-R, C-S, and C-T providing to another six of the half-wave-rectified power supplies.
 28. A process of claim 13, wherein the half-wave-rectified power supplies are twelve, and before the step of adjusting the value of the capacitance, the half-wave-rectified power supplies are powered by an industrial three-phase alternate-current power source connected in a delta type as well as in an inverse-wye type to generate twelve-phased powers named R-S, R-C, S-T, S-C, T-C, T-R, C-R, S-R, C-S, T-S, R-T, C-T providing to twelve of the half-wave-rectified power supplies.
 29. A process of claim 13, wherein each of the capacitance is composed of a variable capacitance. 